Go there; click "Catalog Search"; go to the bottom of the next page that appears and click "Search the Catalog" (don't ask why this is so), then finally do a catalog search with Tolkien as author. When the results appear, seek that which is listed as being published on 09/19/2001 in the right hand column (all eight of 'em: LotR paperback boxed set, Fellowship/TT/return in paperback and then the same combo for the hardcovers), then be aware that the paperbacks will all have silver foil type embossed on the fronts and the hardcovers will have copper foil type embossed on the fronts.

Note that this will look great. Then consider that the box art wraps all the way around. And that the backs of the individual volumes (which you can't see) will have a gallery of character headshots showing 12 characters. And that the hardcovers will have the large format fold-out maps in the back in black and red. And that we've kept the price where its been. And that the HarperCollins editions outside the US will look, umm, different.